The invention concerns a device for adapting a conventional wheelchair for use as a stationary exerciser, and more particularly a device facilitating exercise of arms and upper body which requires no modifications of or attachment to the wheelchair.
Forward extensions of wheelchairs have been proposed to facilitate various forms of exercise or therapeutic activity for their occupants. See for example, U.S. Pat. Nos. 3,405,954 Wolfe; 3,423,086 Moore, and 4,572,501 Durham. Durham does provide for arm exercising but all three in effect require forward extension of the chairs and include ground engaging wheels or support stands.
"Exercise bicycles" are well known. The field may include devices for adapting standard bicycles for stationary exercise--see for example, U.S. Pat. No. 642,919 Knott which discloses a double roller treadmill arrangement for supporting a bicycle's back wheel. The rotation of the rollers may be "braked" to demand more effort from the rider. In another arrangement the bicycle rear frame is supported on a stand so that the rear wheel is free to rotate and its rotation may be variably braked. The common feature of these two examples is that a conventional vehicle is used essentially "as is", without significant modification. As far as bicycle and rider are concerned the stationary operation of the bicycle reproduces very closely its normal operation.
Wheelchairs have been mounted on treadmill-like roller arrangements in ergometric studies. See for example, the work of Brauer, reported in U.S. Pat. No. 4,233,844 Dreisinger. (Dreisinger himself discloses a wheelchair ergometer in which the wheelchair is supported above the ground by its frame rather than its wheels, and energy absorbing means are connected to extensions of the wheelchair axles). As reported by Dreisinger, Brauer's arrangement included two pairs of rollers for receiving the wheels of the wheelchair, with braking or clutching means for at least one of the rollers. According to Dreisinger, Brauer's device was relatively expensive and it was necessary to wheel the wheelchair and subject up an incline and into position on the rollers for measurements to be made.
The arrangement disclosed by Brauer himself ("An Ergonomic Analysis of Wheelchairs", R. L. Brauer, U. of Illionois, 1972) includes closely spaced rollers for supporting the main wheels of the chair while the castering wheels are each supported in short, vertically adjustable channel members.
Dreisinger also refers to a floor mounted motor driven treadmill providing for the use of a standard wheelchair but comments that "it can be quite expensive to install and maintain and provides a possibility of mishap should the subject either fail to keep up with the treadmill or unexpectedly leave the treadmill during an experiment or exercise bout, if no restraining chains were provided."
Dreisinger also comments, writing apparently in 1978, that most of the studies conducted in the area of physical training programs for the handicapped have concluded that there is little benefit to a systematic training program, in improving the physical condition of the handicapped. As a result little work had been done to develop and improve physical exercise equipment for them, and much of the equipment available was developed for use in scientific studies rather than for recreational or exercise use by individuals.
Regardless of Dreisinger's conclusions, at least one more recent attempt has been made to provide an acceptable exercise device for use with wheelchairs for rehabilitation, sports training, or in the home as a muscle toner--see French Patent No. 2,534,806 Jeanmot, filed in 1982. Jeanmot's quite complicated device includes two pairs of rollers, one set for the main wheels and one set for the front or stabilizing wheels of the wheelchair. The two innermost rollers are connected by drive belts, and one of the rollers is braked. There is a ramp at the back to assist in elevating the wheelchair to the level of the rollers. Screw mechanisms at each end of the frame permit leveling adjustment to simulate slopes. The wheelchair frame is secured to the device by means of a telescopic hold down system. Jeanmot appears to suggest that the wheelchair occupant can propel the chair into position on the rollers unassisted, but his ramp appears steep and he does not explain how the relatively small front castering wheels of the wheelchair can safely or comfortably be navigated across the relatively large gap between the main wheel rollers (13 and 14), and the even larger gap between rollers 14 and 15, before reaching their resting place between rollers 15 and 16. (If, as is conventional, the wheelchair's front wheels are freely castering the risk of mishap appears high. Note also that the horizontal spacing between the two sets of rollers must be adjusted to suit the corresponding spacing between the front wheels and the drive wheels of the particular wheelchair). Jeanmot's device by its size, complexity, and apparently heavy weight appears most suitable for institutional use, or at least in a home large enough to have space available for dedication to its use.